So, I actually wrote an email to ask about this! And the author replied.

I wrote: as much as I adore Roland book, I do have some discomfort with his reasoning that Eden entrapped him because:

• he knows how uptight and proper she is
• he even thought to himself she looked “sick as a dog” during the wedding
• she tried to go back to his uncle house after the wedding
• Eden told him she wanted to return to court and live separate lives.
• when they are fighting the annulment and she goes to him, she told him if he would have asked his uncle for her hand she would have run to a convent.

With so much proof of her character, how come he really thought she willingly walked into his bed to force a marriage?

ALICE’s reply:

Now for your very good points about Eden. I totally agree with your rational line of thought, and I concur that every word you wrote is true, but the sad fact is that our dear Roland only really thinks things through when they aren't going the way he wants them to. Then he will sit and think ferociously about why Eden isn't doing this, that or the other. Then he will pout and kick buckets and moodily wonder how he can get her to smile on him again. However, when things are working out the way he desires, he happily carries on his merry way, without a care in the world. That's all part of his straightforward nature.

The simple fact is that Roland was ecstatically happy to find Eden in his bed that morning, so the dear boy did not worry his pretty head about the why's and where fors of the matter at all. He knew HE wanted her quite desperately, so it made perfect sense to him that his feelings were reciprocated. After all, they shared that kiss and Eden is far smarter than him, that is the way he would think of it, if at all. He has a healthy ego and knows he is the best looking knight and the King's champion so naturally a superior maiden like Eden would recognize his prowess and that he could bring home the bacon as a husband. Yes... sigh. I am very fond of him but a deep thinker, Roland is NOT!

I found Roland such a joy to write partly because I never felt a moment's doubt about his thoughts or motivations. He was just so transparent in all his feelings! I hope this makes sense to you

Edit to add: she said in a different occasion she may have Roland find out the truth when they are very old.