Don't know how to feel

So the last few nights I haven't been home. I've been sleeping at my aunts house due to getting out of work late. I do this because she lives around the corner from my job. Today I came home and there's a condom in the trash can. An open condom just out  in the open for me to see...in my kitchen . So obviously I'm curious because I haven't been home so I asked my boyfriend "yo, what the fuck is this ?" He nonchalantly replies "a condom." well no shit Sherlock ! I asked why it was open in he trash . He claims he used it to masterbate . Never has he ever used a condom to masterbate . Right now I'm pretty calm. I'm trying to gather my thoughts and figure out how I should approach this . I mean what if he is telling the truth , but then there's that other hand where he could be lying . Don't get me wrong , I do trust him but only to a certain exstint. I can't say what he wouldn't do because he just might do it. I just find it odd. If anything I need him to understand that this isn't a good look on his part. I need him to see how things look from my side . This does look sketchy . Would do you ladies think?