Urm, very risky for infection unless your OH happens to be a midwife or obstetrician? Which would be convenient if so, but if they were then they would be answering your question and you wouldn’t need to ask here! Please be careful 🩷
Soft means effaced and open means dilation.
Oh my gosh, he should not be doing this 😬😳
As said above, unless he's a medical professional using appropriate equipment and sterilisation then PLEASE do NOT do this. I do not want to scare you because Im sure it's fine but I really would genuinely go get checked by a midwife and explain what's happened because there is a serious risk of infection.
Unless your partner is a medical professional or has training in how to properly do cervical checks I wouldn't bother. If he and you have no idea what it means then I'd assume not and I would not risk doing that