michael
michael would get SO hard just watching you make out with another girl, he would just watch from above as he thrust into you. he would love all the physical contact involved. you guys would all end up in a big sweaty pile by the end of the night.
calum
calum would just be pro at this. he knows exactly how to pleasure a girl. and he would do anything for his girl, if that meant threesomes every weekend
luke
it would take a lot of convincing to get luke to agree to a threesome and this would be all he needed to be completely for it. he wouldn't really know what to do between the 2 girls and he would mostly focus on you but he would still find it hot as hell.
ashton
ashton would try to be super generous and share the love all around between both girls, to make them both feel equally special but he would obviously favor you c: