As far as I know, If He got DV visa then ask your BF to send a letter saying that his status has been change, he got married..Actually, you guys need marrige certificate.If he send letter to KCC then you guys both can have GC from nepal but you have to go Nepal for the interview.But if he comes here in GC status then it will be same process, it may take 5 yrs to get green card and you have to maintain your status.