Short Sketch in Progress - Opinions and Advice?

A young man (BF) is sitting politely on the sofa with his girlfriend (GF) at her Nan's house. Her Nan's very old and sitting in her armchair falling in and out of sleep

Girlfriends phone rings...

GF: (on the phone) "Hello, O-Okay, Sure. Okay I'll pop down right away" (puts phone down)
"I'll be back in about 20 min, Granddad's caught at the shops"

BF: "Okay"

GF puts coat on and leaves

BF is flicking though channels with remote control

10 minutes later... his mobile rings

BF: "Hello? Hi babe everything okay?" (Looks at Nan asleep, & listens to GF's instructions) "What! Pour it out, babe can't I just wait till you come back?? I know I know, look I'm not saying its ‘too much hard work for me' we've been through this Okay, Okay I understand. I will do it" (puts phone down)

He has to empty Nan's catheter!!!

He immediately paces around, looks puzzled, thinks, puts on mature face, paces around more, looks further puzzled, thinks,

"I've changed babies nappies before this is no different!" (he says to himself)

Puts on straight face goes to the kitchen gets a plastic bowl comes out, takes deep breath, paces around, walks over to Nan, tries to lift up her skirt a bit can't find it, looks on other leg, there's allot of awkward fumbling with finally her dress up over her head and him on his knees her many layers of clothing
After a few minutes of this, keys sound in door

GF & Granddad walk in

GF: "What the HELL???!!" (Granddad sees what's going Gasps & goes for him)

BFstressed) "I can't do it babe, I just can't do it?"

GF: "Can't Do WHAT? I Said ‘Cafetière' pour out the ‘Cafetière'.

What are you doing to my Nanna ?"

There's a good joke in there somewhere but at the moment it's a big mess. My advice is to sort out the formatting and then it should make more sense.

Thanks.

If anyone has an idea how best to sort out the format let me know, until then I shall work on it

Any good books on short script layouts ?

It's nothing complicated. So long as you're posting here, this is the preferred format:

INT. BEDROOM - DAY

(that's the SLUGLINE: Internal/External. Location - day, night, later, continuous)

DAVID lays in bed farting about on his laptop.

(this is the ACTION. Only include what can be seen or heard here. You may be tempted to include background information such as how characters know each other - don't do it. When a character is first introduced you should include their name in CAPS. So writers do this throughout their script. They're crazy)

DAVID:
(YELLING) I really should go to the gym and totally gun my quads and shit.

(this is the DIALOGUE. If you want to add detail, such as how the line is delivered, include it in brackets before the line as I've done. Use these sparingly though - never when it's obvious from the dialogue, ie
DAVID:
(ANGRILY) I'll kill you! I'll kill all of you!)

So, this is what you end up with:

INT. BEDROOM - DAY

DAVID lays in bed farting about on his laptop.

DAVID:
(YELLING) I really should go to the gym and totally gun my quads and shit!

David hits "massiveporndeviant.com" in his bookmarks and pulls down his trousers.

DAVID:
Here we go again!

THE END

The main things to remember are to write in present tense, keep your ACTION descriptions as terse and non-novelistic as possible and to not write anything that won't feature directly in your script.

So a rewrite of your sketch might go something like this:

INT. NAN'S HOUSE: LOUNGE - DAY

A young man (BOYFRIEND) sits politely on the sofa with his GIRLFRIEND. Her NAN sits in an armchair falling in and out of sleep.

The Girlfriend's phone rings.

GIRLFRIEND:
(on the phone) Hello, O-Okay, Sure. Okay I'll pop down right away. (puts phone down)
I'll be back in about twenty minutes, Granddad's caught at the shops.

BOYFRIEND:
Okay.

Girlfriend puts her coat on and leaves. Boyfriend turns to the TV and watches some snooker.

INT. NAN'S HOUSE: LOUNGE - LATER

Boyfriend is still watching the TV. The snooker is ending. Boyfriend's mobile rings

BOYFRIEND:
Hi babe, everything okay? (Looks at Nan asleep) What! Pour it out? Can't you do it when you get back? I'm not saying its ‘too much hard work'. Alright, I get it! I'll empty her catheter! Hello? Hello?

He's lost the connection. He paces around, looks puzzled, puts on mature face and paces around some more.

BOYFRIEND:
(TO HIMSELF) I've changed nappies before, I can do this.

He goes to the kitchen and comes back with a plastic bowl. Taking a deep breath he walks over to Nan and lifts up her skirt. There's a lot of awkward fumbling ending with her dress up over her head.

F/X: Keys sound in door

Girlfriend and GRANDDAD walk in.

GIRLFRIEND:
What the hell are you doing?!

Granddad gasps.

BOYFRIEND:
I can't do it babe! I just can't do it!

GIRLFRIEND:
Can't do what? I Said ‘Cafetière'! Pour out the ‘Cafetière'!

THE END

(BTW, I've gone with your BF/GF nomenclature but you'd be better off giving your characters names - makes for a better read I think)

great help, thanks