Help me find this Regency spy romance!

[Ana]

Hi everyone! I read this historical romance years ago from the library — it was a traditionally published book (in print), probably from the late 1990s or early 2000s. I think it was part of a spy series involving a group of titled men (lords, viscounts, dukes) doing secret, low-profile work for the Crown or a hidden society.

Here’s what I remember:
• The hero is wealthy, titled, and working undercover — not an obvious spy, but does quiet jobs for the government or a secret organization.
• He’s charming and flirtatious, possibly known as a bit of a rake.
• He’s always had an interest in the heroine, even before the main events.
• The heroine is bold, clever, and emotionally complex. Possibly red-haired.
• She is not a virgin — she had a past lover who betrayed her and is now blackmailing her.
• She gets injured or compromised somehow (maybe a head injury, possibly while following the hero), and he takes her somewhere safe — maybe his club, maybe home.
• To protect his secret, and/or to protect her reputation, he marries her.
• He later discovers her paying off her blackmailer, and steps in to help. He doesn’t judge her, instead reflects that his own past behavior hasn’t been so noble either.
• Their relationship is full of banter, romantic tension, and emotional honesty.
• The focus is mostly on them and their dynamic — not heavy on spy action.

Here’s an excerpt from the book I’ve always kept!
"Why?" He asked, smiling.
"You're going to make me admit it?"
She exclaimed.
"Aye."
"Very well! I was more interested in you than I had let on."
"There, was that so hard?"
"& I have a confession, as well. I was interested in you, too"
"You were?"
"Couldn't you tell?"
"!..?" She stared at him, wide-eyed and blushing.
"Speechless?" He asked wryly.
—
Just to help, it’s not these:
• My Irresistible Earl (not Mara!)
• Anything by Loretta Chase, Eloisa James, or Joanna Bourne
• I’ve looked into Celeste Bradley, Gaelen Foley, and Shana Galen — no match so far

It was definitely in a library, likely a Zebra, Avon, or Signet paperback — maybe published in the late 90s or early 2000s.

Does this sound familiar to anyone? It’s been driving me crazy! 🙏
Please help me find it!

Ana

[Sharon]

You could try Stephanie Laurens or Elizabeth Hoyt?