Hi Stricktly, yes, as a guy myself, & if you are a good looking sexy babe, it is highly suspicious, it seems to me, of course, it could be an innocent thing & he really is interested in just making the effort to go and calling at yours 'on the spur of the moment' without his gal knowing, just to see you & to say 'HI baby'!
Some guy's are downright sneaky like this, they seem innocent but they can't really be trusted behind their 'current' partner's back.
Also, something as narrow minded, which you didn't have no control of him calling, like this, can even break the friendship bond between you & your pal if your not careful.
As a guy myself, through my own experiences, my feelings, & my past actions, this is my point of view. But now, as a mature person who knows what he want's I am the real me & I don't step on another's toes!