The boyfriend of Becky Watts went looking for her hours after she had been killed, a court has heard.
Teenager Becky had not been replying to Luke Oberhansli's text messages so, on the afternoon of her death, he went to her home in St George, Bristol.
Mr Oberhansli, now 18, said he knocked on the front door and Shauna Hoare - who is accused of murdering 16-year-old Becky - answered.
He said he spoke to Hoare and she spoke to Becky's stepmother, Anjie Galsworthy, and both women went to check the teenager's bedroom - leaving Mr Oberhansli waiting on the doorstep, Bristol Crown Court heard.
Prosecutors allege that by this time Becky was already dead, having been murdered by Hoare, 21, and her boyfriend, Nathan Matthews, 28, in her home.
Her body was then put in the boot of the couple's Vauxhall Zafira car and left outside Becky's house until the evening, when they drove home.
In a written statement, Mr Oberhansli told the court: "I am not aware that Becky had any problems or anxieties about anything. On a day-to-day basis she always seemed happy. She wasn't moody.
"I last saw her on Tuesday February 17. I went around to her house after I finished college. I went up to her room and played on the Xbox. She was playing a game on my iPad. She seemed normal.
"We were texting all day on Wednesday February 18. She was replying quickly until I said I was going to sleep. She said she was in a happy mood. The conversation ended at 11.19pm.
"I got a text at 3.52am saying 'I love you so much'. I was asleep so didn't reply.
"We continued texting the following and everything seemed fine. The last text I sent was at 11.21am."
He told the court he had a dental appointment on the morning of Becky's death, then went to a barber's to get his hair cut, leaving at around 3pm.
"In this time I had made a few attempts to contact Becky by texts, none of which were delivered," he said.
"It was unusual for Becky not to reply so I walked to her house. I knocked on the door and Shauna answered the door.
"I asked if Becky was there, she asked Anjie, Becky's step-mum, who replied that she didn't think so.
"They looked in Becky's room and she wasn't there, so Anjie said she would let Becky know I had knocked when Becky was home."
He added that he remained on the doorstep the whole time.
"I think Anjie said to me it was strange that Becky was not replying to my text messages," he said.
Matthews, of Hazelbury Drive, Warmley, South Gloucestershire, denies murder and conspiracy to kidnap.
He has pleaded guilty to perverting the course of justice, preventing burial of a corpse and possessing a prohibited weapon.
Hoare, of Cotton Mill Lane, Bristol, denies murder, conspiracy to kidnap, perverting the course of justice, preventing burial of a corpse and possessing a prohibited weapon.
Donovan Demetrius, 29, of Marsh Lane, Redfield, Bristol, and James Ireland, 23, of Richmond Villas, Avonmouth, each deny a charge of assisting an offender.
Karl Demetrius, 29, and his partner Jaydene Parsons, 23, both of Barton Court, Bristol, have pleaded guilty to assisting an offender after Becky's dismembered body was discovered in their shed. Both maintain they were unaware of what the packages actually contained.