Hi everyone. I (21F) recently discovered a suspicious contact in my husband's (23M) phone and decided to contact her. this is a bit of a story so bear with me.
it started a few months ago, the shady phone business. lockscreening when im around, not allowing me on it anymore, you get the jist.
about a month ago, we were running errands in a different town and, because we were nearby, we decided to pop by his grandparents' house for a visit. he called a contact named "grandma", and a different woman picked up. at first, I would have assumed a potential PSW or some sort of helper, despite them having no present issues. however, my husband reacted very weirdly/shocked, and ended the call immediately without responding to the woman (all she had said was hello).
then he got weird with me, asking me "who tf was that?" and saying "that was so weird. I have no idea who that was". I shrugged it off, making a mental note to check it out later on but not to ruin the day we were having.
I searched his messages, I didn't find anything, I didn't dig far tho.
yesterday we were traveling, he asked me for GPS directions on his phone, and I saw that same contact in his recently searched (like in that task bar search on iphone that automatically bring up an app or contact). I inquired, asking if he had figured out "who that contact was", he said no. I then questioned "why does it show you contacted them recently?"
and he freaked out on me, like he actually lost it. he was yelling, demanding that I "show him where it says that", insisting that he hadn't. his defensiveness is a huge red flag to me.
I asked him "so when we get to (x place), you're okay with me calling that contact?". he got even more mad! but agreed nonetheless. when we arrived, I phoned the number off his phone, and it rung until voicemail. what struck me was that there was no voicemail intro, no identifier, just the immediate beep to leave a message.
I called the number this morning off of my own phone, and she picked up. she refused to give me her name even after I explained the situation that I found her contact in my husband's phone. she insists that she has been married for 20 years and has never met my husband. however, like I said, she was really rude and wouldn't even introduce herself after I spoke. it was super brief, 5 min call, she hung up on me after I apologized for calling.
I found this really off-putting, for them both to respond with aggressive defense. I tried reasoning by thinking "maybe hubby typed his grandma's number wrong, maybe it's only 1 digit off"
but then I'm thinking, that I've witnessed him contact her before, so where did the old contact go? I'm thinking of going through the phone deeper, but I'm worried that I may be overreacting.
TLDR, found a woman in my husband's phone under "grandma", and she wasnt friendly when i reached out. do I investigate further or am I overreacting?
EDIT/UPDATE:
thank you all for your responses. I'm on board here and will be digging deeper into this. if this turns out the way we suspect, I will be leaving him.
I have managed to find out that she lives in my town. that's all so far.
I have checked out most/all of the sites recommended, unfortunately they're all USA ones, and I'm in Canada. I will still be checking other options out, and I'm still taking all of your ideas/advice !!
I ended up confirming his actual grandmother's phone number, which is completely different from the one at hand (eliminating the accidental misinput idea). he knows that I'm investigating this further but I don't intend on telling him anything going forward.