I feel like Jack would probably have some boundaries though. He probably wouldn't shag your mum, whereas Kyle would.
Kyle would shag your mum and then act like you were being unreasonably displeased. Would definitely try to convince you that you should be flattered because it means he'll still fancy you when you're older.
Jack would flirt with your mum, no doubt, but probably wouldn't actually shag her. Might shag your mum's mate, though, then when he got found out he'd come sidling up to you all like, "we were on a break though, right?"
Phil would not shag your mum. He describes your mum as "ancient" (although not to her face). He shags your 18-year-old cousin, who embarrassingly falls in love with him.
John is scared of your mum, so he shags your sister. Her dishwasher broke, he couldn't resist.