I'd rather have a son. I don't see why his being gay enters into the equation except to imply that having a spobb couch is preferable to having a son who happens to be gay. Homophobic jokes are still homophobic. Calling it a "joke" is similar to mocking an autistic kid for being autistic only to say you were joking.
I am not offended, but you don't know who could be and is too scared to speak up about it.