I'm a teenager and have teenages sisters, so speaking personally I am pretty much the 'leader' being oldest of them all and therefore carry a LOT of responsibility to them. This is because our adoptive mother is seriously ill, my family having respite care while she's in good nursing care in a hospice. These last few weeks have been very tough for all of us teen girls, but my sisters have had boyfriends and all been very well behaved. Maybe my family is in the minority, but we keep very much to ourselves and I for one have no friends outside my family because of personal choice.
My background experience tells me that providing your daughter is made well aware that underage sex is illegal and that her boyfriend respects her as well as respects your wishes. Looking back at how I was at 13, I was an unruly rebellious young teen. But now things have been very different, for I have taken on a lot for someone my age, notwithstanding I'm a mummy.
Two of my sisters bring home their boyfriends. Both guys are very polite, clean cut and well dressed. My house rules in mum Rachel's absence means NO bedroom doors are closed! The doors remain open, propped open and they stay open. Communications between them and me have always been open, friendly, understanding and very respectful: I'm in charge when our aunt is otherwise busy, and I will give out punishment (grounding and removal of privilges) if my wishes are disrespected. So far, not.
Commenting here about going to the movies. As all films are watched in the dark of the auditorium, there is little doubt that quite a lot of kissing gets done between teenagers and probably a great deal of fumbling. xD So what? It's no big deal. And all the films are PG-rated, so teens over here in the UK have to show ID as to their age. Underage film watching, and they're shown the door. So I don't see why they can't go to the movies providing they come back at the time expected.
I loved my boyfriend to bits. he was the father of my child; alas, he died. Okay we went in for underage sex and Juniper is my beloved most adored child I shall ever have. I remember my first and only love with a fondness that still brings tears to my face. For such is young love, tender and sweet. All I can say is you're Mum, you're in charge but don't break your daughter's heart with undue hardness.