Depends on context. Either, admiration of an attractive woman or denigration of an unfavoured female...or an honest description of a romantic encounter. Finally, Victoria Adams' husband.
1. Oooh, that's tasty looking twat.
2. I wouldn't touch her twat with yours!
3. Yeah,I butchered her twat last night.
4. Beckham? Talentless, overrated twat!!