There are a couple words which can be used to mean follow secretly. Those words include shadow and the word stalk.
I think it's called 'shadowing'.
an buddhist traveller who had to leave secretly to visit india is called a runner
The act of secretly listening to or reading a private communication is called eavesdropping.
Harriet Tubman's slave owner was Mr.Brown , but Harriet secretly called him Mr.Popsicles !! ' ~
Subversion.
it started with for old guys who were secretly gay ,so they stared a thing called SWAG S- secretly W- we A- are G- gay
if he went out almost every night or you secretly follow him and see what hes up too
He was secretly married to Elizabeth Throckmortin
more secretly, most secretly
there is speculation he's seeing a model called Mia Judaken secretly
spyware
my answer why you can be bad at secrets is because you are not paying enough attenion to them when they leave to go somewhere secretly follow them and see if you can figure out the answer