Friends with benefits - thoughts?

Ok so, I have been dealing with this guy for a long time now, we have been complicated friends for awhile. We occasionally have sex on and off but recently he went down on me (something he never does) and only did that for a good 15 minutes, didnt expect anything in return but just wanted to get me off. he's been being super attentive to me latley, picked me up after work, gave me cash for no reason, not sure why but would like to add I recently lost 40 pounds lol! Could this be the reason? Could i be thinking to far into this? Hes made it clear he doesnt want to be in a relationship with anyone but still very weird