Red flags or am I going crazy?

My husband and I have three toddlers together and have been together 10 years. He has always been invested in working on various projects but never as much as he currently is.

My husbands best friend owns a few acres of land about 4 miles away from our house. We have a huge yard but it’s not enough to store my husbands many hobbies according to him. As a result of this my husband keeps some of his project vehicles and various other diy projects at his friends house. His best friend has an older male roommate who also lives there and works on various projects of his own in the huge “yard”. My husband has been spending increasing amounts of time over at that house doing his projects. He seems to have gotten very close to the 60 year old room mate and they spend a lot of time together working and talking etc. For context my husband is 30 so I initially thought the friendship was a little bit strange but I didn’t think much of it. Since this friendship developed my husband has been wanting to spend every free minute he has there. After work until late at night and all day every day on the weekend. I showed up there unannounced last week and saw him and the room mate sitting together by a camp fire they made even though my husband told me he couldn’t come home for dinner because he was so invested in his project. Whenever I FaceTime my husband when he’s over working on his projects I always here the old man in the background talking to my husband.

We took a trip to the lake about a month ago for my son’s birthday. We spent the day there and it was great spending time together when without warning the old man showed up. My husband said he had mentioned in passing to the old man that he was going but didn’t think the guy would show up. The man said he showed up because he wanted to meet me? I thought it was weird but again let it go and thought the man just didn’t take social cues well.

This past week I told my husband that I thought he was spending too much time over at his friends house working on various things and I wanted him to stay home to help me with out three kids and stuff around the house. He initially agreed but when he was actually here he spent the whole time sulking. He wouldn’t interact with me at all and acted so mad at me for no reason. My mind started spinning thinking there has to be more going on with this guy than he’s telling me but when I brought it up to him he called me and insane person and said he can’t believe I would even go there. He was so convincing that I ended up agreeing that I was losing my mind and I just let it go yet again. The last three days he has been going back over there to “rearrange his stuff” because we’ve had rain but I noticed the old man has began texting him now. The old man texted my husband yesterday morning saying it rained all night and he was said he didn’t have a woman to cuddle with.. another red flag in my mind. Like what guy texts like that? My husband went over there after he got off work to protect his projects from the rain and then came home after a few hours to eat dinner. After dinner we were on the couch watching tv and the old man texts my husband again and tells him that he’s not going to bed yet and my husband should come back over. Instant alarm bells in my mind. My husband read the text (I saw it before he did because he left his phone on the couch when he went to the bathroom) kissed me all sweetly and asked if I cared if he went back over. I said “so you can hang out with your boyfriend?” and he just looks at me rolls his eyes and says I’m just telling him I’m bit coming over. After he sent the text he was so mad HE WENT TO BED. He then texted me during his lunch break at work today and told me he would be going over to the house again after work on some stuff. I just didn’t respond.

All of this is weird right?! Am I being insane because I feel to totally crazy. Any input would be appreciated.