Yeah Alexis introduces mc to her dad as layla's boyfriend too and he eats with the monroes like a part of the family, it doesnt get much more official as that at this age without a proposal lolI still need to play her path in the update she is last on my list of solo paths. But I would say they are unofficially official when the MC sleeps with her as it feels like a pretty damn romantic date and everything. Or I would say at the very least I think Layla would consider them official because if you choose Elena if on her path you basically break Layla's heart.