Is my boyfriend still in love with me?? or is there somome else..?

well my boyfirend went to a hotel party last friday. and he told me that he had a good converstaion with this girl destiny, that he had just meant. and he told me that she sat at his lap in the car becuase there wasnt enough room in the car and he said that he danced with her a little bit and his friend gave him a weird look. and he told me that he could tell that the girl liked him and he gave him her phone liek she wanted his number and he just haned it back to her and she gave him a weird look should i belive that?? and it seems to me that my boyfriend haves been spending alot more time with his friends then me. and he says he loves me and he will never leave me for any girl. even though he left his girlfriend for me.. me anfd him have been together now for 8 months which is his longest and most serious relationship,. and he tells me he wants to marry me and have a future with me so what should i do?? what do you think???