We've been close friends for a long time and you know that I have chosen to remain child free not because I despise children; they just hold no interest for me. I don't feel there is a place for them in my life, something we've talked about before.

I wouldn't want to hurt you by explaining that my feelings apply to your child as well. I don't dislike your daughter – like most well-behaved children, she can be charming. But to me she is a stranger whose language I cannot speak.

I care about you and your life, and I'm delighted you're so happy being a mum, but there's something I am never allowed to say: I find your child tedious. It's not personal; that's how I feel about children in general.

I am at a loss for a response when you tell me I'm lucky to have time to go to the gym, to be able to take spontaneous weekends away, to have two spare bedrooms. I want to remind you that you gave all that up for parenthood and only two minutes ago you told me that you've never been happier. I'm not lucky; we both had choices, we just want different things from life.

The hardest thing about it, though, is the subtext – what I know you're really thinking but will never say. I heard it last week when, as I showed you the gym in my new house, you looked around and said, "Oh well, you can turn it into a playroom if you change your mind." You think my life choice is less sincere, less enduring, less fulfilling than yours – and that's what I really resent.

• Tell us what you're really thinking at mind@theguardian.com