furtively russian

• подложи́ть

  lay, put, line, add, put some more, put furtively, plant (eg bomb)

• подкла́дывать

  lay, put, line, add, put some more, put furtively, plant (eg bomb)

• подгля́дывать

  peep, watch furtively, spy

• воровато

  stealthily, furtively, thievishly, on the sly

• подсма́тривающий

  peeping, spying, watching furtively