I've been dating this person for months, I'm not at all unsure about my feelings towards them. But recently I become more aware of a close friend of them, and how they are as a person and such. Since this I haven't been able to stop thinking about this friend of them, they're constantly on my mind. But the thing is I'm unsure why this is, I haven't interacted with this friend I only know what I know from my partner, we're quite similar in our interests and such. In other words I am completely unsure about my feelings for this friend of my partner.