A motorcycle accident has again landed Dean McDermott in the hospital – this time in the intensive care unit with a punctured and collapsed lung.

"He's in a lot of pain," Tori Spelling, who has been by her husband's side since the accident (his second on a cycle this year), tells PEOPLE. "He's taking this as a sign and realizing family is too important to risk his life."

The reality star, 43, crashed on Tuesday, while dirt bike riding with two friends. After the crash, he couldn't move and was bleeding heavily from his right side with a puncture wound. He was taken straight to the intensive care unit at a Los Angeles-area hospital and, says Spelling, is expected to make a full recovery.

On Thursday McDermott felt well enough to Tweet. "Thanks for the well wishes. A collapsed lung is no fun, and is a lengthy heal. Feeling pretty bad today. Day 2 is always the worst," he writes.

Spelling, 37, whose new book, uncharted terriTORI, has just been released, recounts to PEOPLE how she found out. "His friend called me and said he was in the ER," she says. "He didn't want to scare me so he just said he had a crash and that they were X-raying him."

"At first I was mad," she says. "I was pissed that he was out biking and crashed. But when I showed up and saw him lying there, and they told me they were admitting him to ICU with a collapsed lung, my heart dropped. My biggest fear had come true."

Earlier this year, McDermott fractured his shoulder in a motorcycle accident. As fans of the couple's Oxygen reality show Tori & Dean: Home Sweet Hollywood know, the two have had an ongoing disagreement about the dangers of his high-octane hobby.

After the first accident, they compromised and McDermott agreed to give up professional racing and only ride recreationally. This time, he's promised his wife to never ride again and to get rid of his bikes.

"When I first saw him he just softly said 'I'm so sorry,' " Spelling recalls. "I just held his hand and cried. That's when he said, 'I'll never do this again. You and the kids mean everything to me.' "

The couple are parents to son Liam, 3, and daughter Stella, who recently celebrated her 2nd birthday with a Barbie-themed party.

McDermott is expected to remain in intensive care a few more days.