Should I marry my brother-in-law?

I lost my husband two years ago and my in-laws, most especially my brother-in-law supported me through my most trying moment.

He promised to be there for me and also to look after my two children, which he has done tirelessly without asking anything in return.

There's no day that passes without him calling to check on us and he visits us every weekend.

Eventually, we became so close that when I get a problem, he is the first person I call.

However, recently he told me that he is in love with me and that he wants to marry me.

I think I love him too but how will our relatives react?

It also feels like I'm betraying my late husband.

What should I do?

Asumputa