Buttplugs ousted anal in our couple sex life, and I am very sad

Hi, my wife \[42\] – we are actually not married, but we have a son and we are in an exclusive relationship so I use wife – and me\[52\] are together since 2015. We have, I think, a good sexual relationship, more or less comparable sex drives, similar tastes. We started to do anal almost casually more or less after 3 months that we started to fuck. I say casually because I started to play with her anus during sex, she showed to like it and from there it’s a slippery – as in lubed – slope. We both discovered that we both had anal sex before and we enjoyed it. Since then we had anal sex let’s say once in ten, never kept a log but more or less should be like that. Three years ago I gave her as a buttplug as birthday present (smallish, classic shape, with an internal ball that adds something to the experience she says). Since then other plugs, in different shapes and sized were added to the collection, and she almost always wears it during sex, which is very satisfying for both of us. But there is a but: we practically stopped to have anal sex, I mean my penis is not allowed in her anus anymore, which is really saddening, at least for me. I talked with her about it, but she tells me that while she enjoys the plugs, my cock, which is on the average/smallish size, gave her some pain afterwards. Please note that yes we use lube, a lot, and she never told me so before. Something actually changed in the meantime: we have a son now, so less time to have sex in a proper relaxed way, so maybe this is the reason, but FUCK! I loved anal. OK, I just wanted to share, I’ll live with it, and maybe something will change.