Bipolar...how to take what my friend is doing/acting towards me?

i have a good friend... at times FWB that suffers with bi polar... ive known him about 9 months... anyway..the week before st pattys he called me which he does do every once in a while..usually i call him but he had some good news and wanted to know had i eaten, he had supper ready... so i went over (plus hes a good cook)...and stayed the night...then after i couldn't get a hold of him for over a week until st pattys... and he answered my call and was just very agitated/irratable and told me he just wanted to be alone, its not me, just where he is at right now and he was looking forward to his lease being up with his cousin so he could live alone...so i didn't take it to personally based on that...and i said well you know... can i come over for a little while, sure but he said it wouldn't be a good idea for me to stay over and when i said why he gave me the spiel about how he wants to be alone...