Advice on an inappropriate request?

My boyfriend is hosting a party on July 4. His childhood friend from LA will be attending with her daughter. There will be other guests at the party as well. The husband of his childhood friend, whom my boyfriend does not know personally, called up and asked if he could come as a surprise to his wife. They have some marital issues. He wanted to make up by dropping in by surprise. I think this is very inappropriate of him to make this request. Not knowing the marital issues they have, his wife could freak out and make it very awkward for every one in the party. Furthermore, none of us knows him. What to do? Let him know that he is welcomed but then what??? Thanks, mc