He is just so vain he revels in the attention from Craig. The constant stoking of the ego is just too irresistable to his already over-inflated opinion of himself.
IF he is straight, has he considered how it looks to the outside world to be seen sucking a gay guys fingers, and being constantly massaged and feted over?
His "date" with big brother was very revealing..his lack of conversational ability, even though he thought he was being witty, his lack of knowledge about what food he was eating, and his rushing to take his kit off at the first opportunity and show us his "stripper moves".
The guy is a dopey little idiot who lives with his mummy and hasn't got a clue about the world in general.