Are you sure it's a man ? If it is then tell your Dad to grow up!
Homosexual - dictionery definition = a person, especially a man, who is sexually attracted to people of the same sex and not to people of the opposite sex
Depends if he only tries to kiss me or if he tries to kiss women too I would say. And most straight men take any excuse to 'drag up' so the make up thing is no sign at all!
I would ask him if he was gay not just presume. Men who are secure in their sexuality should be able to express their feelings. Depends on circumstances too. My brother wears lip gloss and kisses both his own Dad and his son - in my book that makes him a decent bloke!