I wasn’t convinced by the purported message that father realises he loves his son. It seemed more as if he only wanted what he could no longer have: unlimited contact with the child, which he had previously frittered away, to the point of missing his son’s birthday to have casual sex.
More than the above, I just didn’t find it funny. Slapstick and clowning around may be some people’s cup of tea, but not mine. It didn’t even raise a smile from me.