The TV star jokingly suggested that his co-host was "very, very happy" about something in her personal life live on Good Morning Britain earlier today.
After commenting on Susanna's posture, Piers, 53, teased: "I know you're happy. You're very, very, very happy."
The 47-year-old star giggled back at him as she claimed she was simply "relaxed".
Later on in the show, the outspoken presenter joked once more: "I don't know what else is going on in your life."
Susanna, who proceeded to placed her head in her arms, has three children – Jack, Sam and Finn – by her ex-partner Dominic Cotton.
She is currently single, but hinted in June that she "wasn't entirely single".
The presenter was left blushing on Good Morning Britain when Piers quizzed her about her dinner dates with a mystery man.
Reading from an issue of the Radio Times, he quoted: "She hasn’t been 'entirely single' since they [referring to ex partner Dominic Cotton] separated.
"She’s had some 'nice times' with men."