Should I speak to my daughter's boyfriend about his underage drinking?

I have two very smart daughters, 21 and 15 1/2. The 15 year old is dating a 17 year old boy who drives ( he is also very intelligent). Both of my girls are very opposed to underage drinking. There has been some drama in their relationship, but we are attributing the drama to their ages. My daughter is very upset with him because he went to a party last night and drank. He was with her (she was sick) in the early part of the evening and then left to attend this party, even though he is very well aware of where she stands on the subject. She was hurt because he left her when she was sick to partake in an activity that she very against. He usually babies her when she is hurt or sick, so it isnt a matter of him being afraid that he will catch the illness. He knows she is mad at him and told her that he was sorry, but was sort of sarcastic. Should my husband and I have a talk with the boyfriend to let him know where we stand on the matter? also, who thinks he was a jerk for leaving her?