Kyle spent some time with Jane but he couldn't stay there for too long because this was her workplace. He had to leave soon before he caused her any trouble, he knew that buying everyone a phone might have been a little overboard but he had a point to prove.
A dick-measuring contest if you will but this resulted in Kyle being the victor as Mike was put in his place. Mike didn't like Kyle but Kyle didn't care, Mike couldn't make any meaningful contribution to his life after all.
This was the perfect scenario but Kyle knew it was time to go, planting a kiss on Jane's forehead before leaving.
It was him marking her and letting everyone in that store know she was his, he could recognize the look of a man interested in a woman.
Mike had those eyes and Kyle made sure to let him know to stay off, this was the only thing he could do even though he trusted Jane enough not to entertain another guy.
