My Sister In Law

Im confused and want other girls opinions about something. I have always thought of myself as being straight as i have always had boyfriends and am currently married to my husband. Although, lately ive been having second thoughts. It all started at my Sister in Law Tashas birthday pool party this year. Tasha is curvy but had on this small bikini that barely covered her big boobs and fat ass. Watching her turned me on so much that my bikini bottoms started to get wet. I texted my husband to meet me in the bathroom as i was really horny. He thought i was just in the mood and wanted his cock but the whole time he was fucking me, i was thinking about her big boobs in my face. What does this mean? Im so confused.