He stares into your eyes It may seem a cliche, but there is definitely truth in this one.
Did he let you finish the last bit of his cheesecake in the coffee shop? Well, ladies, put those worries to rest.
On the other hand, if he is disrespecting you constantly, making you feel bad about yourself and not caring about what you have to say, you need to run for the hills.
Healthy friendships are welcome as long as strong boundaries are in place.
In this case, he might offer to pick you up before you join everyone else, or subtly gravitate towards you if he sees you sitting by yourself.