Nope, you're not and you have every reason to be suspicious and ill at ease. This is not a normal situation she is putting you in and it is not at all how it should be. An established old friend that had a relationship with her but she continued with when she met you might be acceptable but only rarely.

First off, he's not only an ex boyfriend calling her for support which he should not be doing anyway, he has admitted to being in love with her still. Regardless of her intentions, like if she is just being her supportive personality or not, his intentions are questionable at best. Just the fact that he brought up that he still is in love with her shows that there are reasons other than something innocent in what he is doing. It should be her place to say no, and she should question his motives just as much and that she is not, and giving into it makes me question her motives and feelings here also.

Considering the situation and his feelings, you have every right to ask for this not to continue but don't complain or say anything if you intend not to do anything about it. You have to make a choice here. Either she gives you reason to know she's exclusive to you and all yours, or not. AT that point, if she doesn't you have to either accept she's not serious and decide if that's ok or not with you or move on down the road to find someone that's going to actually be loyal and devoted to you.

She's playing with fire and you just may want to get out of the way before it all blows up in your face.

In summary please don't feel that you are being a paranoid or jealous bf but know that your thoughts and views on this are very valid. Just don't sit on it and let it escalate.