Is he trustworthy or im insecure?

My bf of 3 yrs hasnt cheated on me, but hes been following local women on social media, one after another, and lies about it. Is it true that you can send a facebook friend request to someone whos profile were private, and follow them? And then once they make their profile public, you automatically follow them? He said thats the reason why it showed on his activity log that he follows a lot of women. Anyways, i didnt really believed him, hes still following girls after another. Now, hes looking for a new job, theres this job that a lot of women works there. I even met him through a job too while i was still on a break w my ex bf. He didnt know at first that this place has more women working there, so he didnt seem as interested, and was still looking for other jobs. Until after i told him, i know a lot of women working there, and he began having so much interest in it. He denied his other work offers, putting all his hope into that specific all women job. Should i be concerned?