Ashton- Ashton asks you out via skype call you had been best friends for months and you both had feelings for each other he was on tour while you was in college he skyped you hourly when he could and this one paticular time he skyped you and asked you to be his
Luke- Luke asked over a romantic lunch
Calum- Calum asked on twitter
Michael - Michael asked you at an awards ceromony when he was saying his dedications